Question

Two parallel straight wires 53.0 cm apart carry currents in opposite directions. Current = 10.0 A is out of the page, and /2 = 8.0 A is into the page. Determine the magnitude and direction of the magnetic field halfway between the two wires.

Answer 1

Given:

$I_1=10\:\rm A$

$I_2=8.0\:\rm A$

$d=0.53\:\rm m$

The net magnetic field

$$B=B_1+B_2$$

$$B=\frac{\mu_0I_1}{2\pi\ d/2}+\frac{\mu_0I_2}{2\pi d/2}$$

$$B=\frac{4\pi*10^{-7}*10}{2\pi*0.53/2}+\frac{4\pi*10^{-7}*8.0}{2\pi*0.53/2}=1.4*10^{-5}\:\rm T$$

Net magnetic field is directed upward.